1. Field of the Invention
The present invention relates to a lift for lifting and lowering a body such as a human body and a load smoothly and continuously with a small power, and more particularly to a lift for lifting and lowering handicapped people.
2. Description of the Prior Art
Usually, for nursing handicapped people, for example, lifting/lowering them to/from a bed and giving them a bath, many kinds of lifts for lifting and lowering a human body with a small power are provided. These lifts employ a human power such as a gear, a pulley and a screw, and also employ an external power, for example, electric power, oil pressure and water pressure.
A winding winch is provided for a lift using a human power, such as a gear, a pulley and a screw. In this case, a ratchet gear mechanism having a back-stop claw as a lowering stop mechanism is utilized when a body is lowered gradually.
This mechanism, however, needs a gear and a claw, therefore its size becomes large and its lowering speed is not smooth, because it rewinds the wire wound around the winch by reengaging the claw.
Although a screw system can provide a continuous smooth lifting and lowering, it needs a long screw having many screw threads for moving for a long distance, so the system cannot be small size.
In a lift using an external power, for example, electricity and water, lifting and lowering are smooth and it can stop while lowering, however, the equipment thereof is complicated and the product price is rather expensive.
In this way, there are many kinds of technologies for lifting and lowering the body including the human body and the load, but they have demerits as stated above. There have been longing a lift lowering a body continuously and smoothly which is used for lifting and lowering a seat of a wheelchair and a simple lift used for helping people confined to bet to change the bed seats and a futon (bedding) and to care for their toilets, or a small sized and light weighed portable lift which is used for going up or going down the stairs.